Notices to Readers
Change of Dosing Regimen for Malaria Prophylaxis with Mefloquine

CDC recommends mefloquine (Lariam R) alone as the drug of
choice for malaria prevention for travelers to areas with
drug-resistant Plasmodium falciparum malaria (1-4).* Based on
accumulating experience with this drug, the prophylactic dosing
regimen has been revised to a single dose of mefloquine to be
taken every week (3). The first dose should be taken 1 week
before travel. It should be continued weekly during the entire
period of travel in malarious areas and for 4 weeks after
departure from such areas.

The previous dosing regimen (in which one dose was taken each
week for 4 weeks, followed by one dose every other week)
compromises the effectiveness of mefloquine. Malaria prophylaxis
with this dosing regimen among Peace Corps volunteers in West
Africa was less effective than expected (5). The relatively low
effectiveness was due to the every-other-week dosing regimen
because all mefloquine prophylaxis failures occurred during the
second week of the alternate-week dosing regimen in volunteers
who had used mefloquine greater than 2 months. Mean mefloquine
blood concentrations were substantially lower during the second
week of the every-2-weeks dosing regimen than during the first
week, suggesting that during the second week blood levels are too
low to suppress parasitemia (5).

All studies confirm that mefloquine is well tolerated when used
for prophylaxis. No serious adverse reactions to mefloquine
prophylaxis (i.e., psychoses and convulsions) have been observed
among Peace Corps volunteers or among 18,462 persons enrolled in
prophylactic drug trials and surveys of travelers who were taking
mefloquine weekly (5). However, serious adverse reactions have
been reported, especially when mefloquine was used for treatment
of patients with malaria. Because mefloquine has been used in the
United States for only 18 months, monitoring of adverse reactions
remains important. Physicians are encouraged to report serious
adverse reactions in persons using mefloquine to CDC's Malaria
Branch, Division of Parasitic Diseases, Center for Infectious
Diseases; telephone (404) 488-4046.

Consistent with previous guidelines, mefloquine is not
recommended for use by travelers with known hypersensitivity to
mefloquine; children less than 15 kg (30 lbs); pregnant women;
travelers using beta blockers; travelers involved in tasks
requiring fine coordination and spatial discrimination, such as
airplane pilots; and travelers with histories of epilepsy or
psychiatric disorder (1,2).

Travelers to areas of risk where chloroquine-resistant P.
falciparum is endemic and for whom mefloquine is contraindicated
may elect to use daily doxycycline alone or chloroquine alone. If
chloroquine is used, the traveler needs to be aware of the need
to seek medical attention for febrile episodes and to carry a
treatment dose of pyrimethamine-sulfadoxine (Fansidar R) to be
used if medical care is not available within 24 hours (1,2).

The CDC publication Health Information for International Travel
(2) provides detailed information for each country on the risk
for malaria to travelers and on the presence of drug-resistant P.
falciparum (1). Health information for travelers is available 24
hours a day from the CDC automated telephone system at (404)
332-4555.

Periodic shortages of mefloquine have occurred in the United
States. Travelers who cannot obtain mefloquine before departure
may be able to purchase it in Europe while in transit to
countries with endemic malaria. Prescriptions written in the
United States are accepted at airport pharmacies in Frankfurt and
Paris (both Charles de Gaulle and Orly airports). The pharmacy at
Heathrow Airport in London requires prescriptions written in
Great Britain. At the airport pharmacy in Brussels, a
prescription from the airport physician is required. Mefloquine
is not available at the airports in Amsterdam and Rome and at
Gatwick (London).

In some countries, a fixed combination of mefloquine and
pyrimethamine-sulfadoxine is marketed under the name Fansimef R.
Fansimef R should not be confused with mefloquine, and it is not
recommended for prophylaxis of malaria.
Reported by: Malaria Br, Div of Parasitic Diseases, Center for
Infectious Diseases, CDC.

References

CDC. Recommendations for the prevention of malaria among
travelers. MMWR 1990;39 (no. RR-3).

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